Sweetwilliam
Dianthus barbatus
Last reviewed: June 2026
Dianthus barbatus (Sweet William) is a fragrant forb native to North Carolina that blooms from May through July. This adaptable plant attracts bees, butterflies, and moths with its colorful clustered flowers.
Sweetwilliam is toxic to dogs and cats.
Listed as toxic by the ASPCA Animal Poison Control Center (opens in new tab) (last reviewed 2026-05-21). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435and your veterinarian's emergency line.
Pollinator Patch flags toxic plants so you can choose a pet-safe native alternative for your yard.
Light
full sun
Water
medium
Size
12"–24" H × 12"–18" W
Bloom
May, Jun, Jul
Native to
NC
Pollinators
bees, butterflies, moths
Sweet William produces clusters of fragrant, colorful flowers in shades of pink, red, white, and purple from late spring through summer. This compact biennial forms neat clumps with narrow green leaves and reaches 1-2 feet tall. It's perfect for borders, cottage gardens, and cut flower arrangements.
Growing Sweetwilliam
Grow Sweetwilliam in full sun and medium water. Mature plants reach 12 to 24 inches tall and spread 12 to 18 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Sweetwilliam is an HOA-friendly choice. Maintenance level: low. Tidiness: 4 out of 5.
Works well in: front yard, foundation, street edge, mid zone.
Wildlife value
The fragrant blooms attract bees, butterflies, and moths throughout the extended flowering period. The clustered flower heads provide an excellent nectar source for pollinators during peak summer months.
Common questions
- When does Sweet William bloom?
- Dianthus barbatus blooms from May through July, producing clusters of fragrant flowers during late spring and early summer.
- What pollinators visit Sweet William?
- Sweet William attracts a variety of pollinators including bees, butterflies, and moths, making it valuable for supporting native pollinator populations.
- What growing conditions does Sweet William prefer?
- Sweet William thrives in full sun to partial sun locations and adapts to various moisture levels from low to high water conditions.
- Is Sweetwilliam toxic to dogs?
- Yes. Sweetwilliam is listed as toxic to dogs by the ASPCA Animal Poison Control Center (aspca.org). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Sweetwilliam toxic to cats?
- Yes. Sweetwilliam is listed as toxic to cats by the ASPCA Animal Poison Control Center (aspca.org). If your cat has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Sweetwilliam HOA-friendly?
- Sweetwilliam is generally an HOA-friendly choice in the right placement, with low maintenance.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Pollinator Patch flags toxic plants like Sweetwilliam and shows pet-safe natives for your ecoregion instead.
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